AB1230 EVALUATION OF THE STRUCTURAL MODIFICATION OF THE SUPRASPINATUS TENDON BY COMPUTER ANALYSIS OF ULTRASOUND IMAGES THROUGHOUT THE EVOLUTION OF TENDINOSIS.
Authors: M. Tortosa-Cabañas, C. Guillén-Astete, Á. Andreu-Suárez
Journal: Annals of the Rheumatic Diseases (2022)

Background In subacromial pain syndrome, the supraspinatus tendon is the most frequently injured. Supraspinatus tendinosis is a structural lesion of the tendon stroma whose ultrasound diagnosis depends largely on the observer. Due to this, the follow-up is mainly clinical, based on ordinal scales of pain or mobility. The computer analysis of the image has been recently integrated into the musculoskeletal pathology, but the evidence in ultrasound is very limited. Objectives To evaluate the computer analysis of the ultrasound image of the supraspinatus tendon at diagnosis and during evolution depending on the treatment administered. Methods A retrospective study was carried out based on the ultrasound records of patients diagnosed with supraspinatus tendinosis between 2014 and 2020. All images were obtained with the same ultrasound equipment. The records had to fulfill the following characteristics: (i) Absence of direct or indirect ultrasound signs of fibrillar continuity solution, (ii) absence of calcifying lesions and (iii) availability of an ultrasound study 5-7 months after diagnosis with the same frequency, gain, and depth parameters for each case. The ultrasound images showing tendinosis were analyzed using the ImageJ 1.53e program. The means and modes of the grayscale signal intensities were determined in longitudinal and transverse projection for each image. For the statistical analysis, paired before-after comparisons based on the normal distribution were used, grouping the patients according to the injured tendon area (lateral, central, medial) and the treatment administered. To determine the weight of the variables analyzed in the probability of resolution, a forward modeled binary logistic regression was performed using the Wald method. Results Records of 35 patients were included: 10 treated with immobilization, 12 with corticosteroid injections and 13 with physical therapy. Table 1 summarizes the demographic and clinical characteristics of the population. Table 1. Demographic and clinical characteristics of the population. GI: gray intensity according to longitudinal or transverse axis. SD: standard deviation. Treatment group Physical therapy Immobilization Injections Mean SD N (%) Mean SD N (%) Mean SD N (%) Age 55 8 54 10 56 10 Sex Women 11 (84,6%) 7 (70%) 9 (75%) Men 2 (15,4%) 3 (30%) 3 (25%) Injured area Central 1 (7,7%) 0 (0%) 1 (10%) 0 (0%) Lateral 5 (38,5%) 3 (30%) 3 (25%) Medial 7 (53,8%) 6 (60%) 9 (75%) GI Long axis. 79,209 20,127 69,953 14,815 82,213 33,638 GI Trans axis 81,840 17,291 74,091 19,639 3 (25%) 85,991 34,520 The changes observed in the mean gray intensity in the longitudinal projection of the tendon did not correlate with the fact that the patients were discharged (0.006 SD 10.47) or not (2.231 SD 7.8835) after the second evaluation (t=-0.708, P=.484). In contrast, the gradient of the mean gray intensity in the transverse projection of the tendon showed significant differences between patients discharged (9.268 SD 3.752) or not (-0.2054 SD 5.26), (t=6.162, P=.000). On the other hand, in the group of patients discharged, a greater reduction was observed in the dispersion of the mean gray intensities (-11.08 SD 5.843) compared to the group that was not discharged (1.178 SD 1.859), (t=-8.458, P=.000). In the multivariate logistic regression analysis, only the final dispersion of gray intensity was associated with the discharge condition with Coef. B=-0.096, P=.027, HR 0.908 (95% CI: 0.834-0.989). Conclusion Computer analysis of ultrasound images of the supraspinatus tendon in patients with pure structural tendinosis distinguishes a favorable clinical course only in the study of the cross-sectional projection, probably due to the more flattened shape of the tendon. Clinical resolution, understood as medical discharge after the second evaluation, is associated with an increase in the mean intensity of grays but especially with a reduction in the dispersion of grays. Disclosure of Interests Marina Tortosa-Cabañas: None declared, Carlos Guillén-Astete Speakers bureau: Novartis, Janssen, Abbvie, Grunenthal, UCB and Gebro, Paid instructor for: Roche, Novartis, Janssen, Esteve and Menarini, Consultant of: Janssen, Novartis and Roche, Grant/research support from: Pfizer, Grunenthal, Gebro and Novartis, África Andreu-Suárez: None declared